Computational thinking (CT) has become a skill that is taught starting from an early age with its increasing popularity. In addition, the opinion that CT is related to other 21st century skills finds its place in the literature. The main purpose of this study is to identify the contributions of scaffolding-based game programming activities to students' CT and 21st-century skills. In line with this purpose, the study was designed as a qualitative case study. The participants of the study consisted of 16 primary school students, 10 pre-service ICT Teachers, and 2 primary school teachers. The research results reveal that game programming has a positive effect on students' CT skills, 21st century skills and some psychometric variables like self-confidence and motivation. In future studies and implementations, educators may support their instructions of programming through different scaffolding strategies. In addition, it should be taken into consideration that students can become innovative designers with content that they find interesting.